A French engineer kidnapped in northern Nigeria 11 months ago says he escaped his captors on a motorcycle, without a ransom being paid, and will return to France immediately.

Kaduna State Police Commissioner Olufemi Adenaike says Francis Collomp escaped from his abductors in Zaria and went to the nearest police station. Collomp was reported to be weak and to have lost a lot of weight, but was not injured.

French President Francois Hollande said he was happy Collomp had freed himself, but said he has not forgotten seven French citizens who are being held in Nigeria, Syria and Mali.

Police say about 30 men stormed Collomp's home on December 19, 2012, his 63rd birthday, and took him prisoner. They killed a neighbor and a security guard in the attack. The Boko Haram splinter group Ansaru claimed responsibility for his kidnapping.

Last week, the United States labeled Boko Haram and Ansaru foreign terrorist organizations. On Saturday, Nigerian security forces raided a Boko Haram stronghold in the state of Borno, claiming 20 militants were killed in the firefight.